Source code of Windows XP (NT5)
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117 lines
2.7 KiB

/*
* Cx5520.C - Cyrix Cx5520 PCI chipset routines.
*
* Notes:
* Algorithms from Cyrix Cx5520 Data Sheet
*
*/
#include "local.h"
/****************************************************************************
*
* Cx5520SetIRQ - Set a Cx5520 PCI link to a specific IRQ
*
* Exported.
*
* ENTRY: bIRQNumber is the new IRQ to be used.
*
* bLink is the Link to be set.
*
* EXIT: Standard PCIMP return value.
*
***************************************************************************/
PCIMPRET CDECL
Cx5520SetIRQ(UCHAR bIRQNumber, UCHAR bLink)
{
UCHAR bOldValue, bNewValue, bOffset;
//
// Validate link number.
//
if (bLink > 4)
return(PCIMP_INVALID_LINK);
bOffset = (UCHAR)(((bLink - 1) / 2) + 0x5C);
bOldValue = ReadConfigUchar(bBusPIC, bDevFuncPIC, bOffset);
if (bLink & 1)
{
bNewValue = (UCHAR)((bOldValue & 0xF0) | (bIRQNumber & 0x0F));
}
else
{
bNewValue = (UCHAR)((bOldValue & 0x0F) | (bIRQNumber << 4));
}
WriteConfigUchar(bBusPIC, bDevFuncPIC, bOffset, bNewValue);
return(PCIMP_SUCCESS);
}
/****************************************************************************
*
* Cx5520GetIRQ - Get the IRQ of a Cx5520 PCI link
*
* Exported.
*
* ENTRY: pbIRQNumber is the buffer to fill.
*
* bLink is the Link to be read.
*
* EXIT: Standard PCIMP return value.
*
***************************************************************************/
PCIMPRET CDECL
Cx5520GetIRQ(PUCHAR pbIRQNumber, UCHAR bLink)
{
UCHAR bOldValue, bOffset;
//
// Validate link number.
//
if (bLink > 4)
return(PCIMP_INVALID_LINK);
bOffset = (UCHAR)(((bLink - 1) / 2) + 0x5C);
bOldValue = ReadConfigUchar(bBusPIC, bDevFuncPIC, bOffset);
if (!(bLink & 1))
{
bOldValue >>= 4;
}
*pbIRQNumber = (UCHAR)(bOldValue & 0x0F);
return(PCIMP_SUCCESS);
}
/****************************************************************************
*
* Cx5520ValidateTable - Validate an IRQ table
*
* Exported.
*
* ENTRY: piihIRQInfoHeader points to an IRQInfoHeader followed
* by an IRQ Routing Table.
*
* ulFlags are PCIMP_VALIDATE flags.
*
* EXIT: Standard PCIMP return value.
*
***************************************************************************/
#ifdef ALLOC_PRAGMA
PCIMPRET CDECL
Cx5520ValidateTable(PIRQINFOHEADER piihIRQInfoHeader, ULONG ulFlags);
#pragma alloc_text(PAGE, Cx5520ValidateTable)
#endif //ALLOC_PRAGMA
PCIMPRET CDECL
Cx5520ValidateTable(PIRQINFOHEADER piihIRQInfoHeader, ULONG ulFlags)
{
PAGED_CODE();
return ((GetMaxLink(piihIRQInfoHeader) > 4)? PCIMP_FAILURE : PCIMP_SUCCESS);
}